This invention generally relates to power supplies. More specifically, the invention relates to power supplies that are used outdoors.
Power supplies such as welding power supplies are used to provide high-amperage current. Typically, in a welding power supply, a pair of output terminals is provided. A welding cable connected to the welding torch (or stinger, drive assembly or welding circuit) is inserted into one of the two output terminals. The other output terminal receives a welding cable that is connected to the workpiece being welded. Typically, the connectors are twist-lock type connectors (also called xe2x80x9cinternational connectorsxe2x80x9d), the power supply has a female connector, and the welding cable has a mating male connector. In some designs the cable has a female connector and the power supply a male connector.
Engine-driven welding power supplies are well known, and may be driven either by a DC generator or an AC generator (also called an alternator-rectifier). An AC generator generally includes, in addition to an alternator, a reactor followed by rectifiers to provide a DC output. Electrical power produced by the generator as the engine drives rotation of the rotor is converted by known electrical components into useable welding power and auxiliary power available at respective terminals.
It is not unusual for welding power supplies to be used outdoors, for example, at construction sites. Thus, they are often exposed to rain or may otherwise get wet. Also, to obtain IEC certification (or other certifications such as UL, CSA, NEMA, etc.), welding power supplies must be subjected to a xe2x80x9crain testxe2x80x9d. In such a test, the power supply will be exposed to water to ensure that premature failures in the field will not occur.
In one type of prior art connector for a welding power supply, a twist-lock receptacle, which receives the end of a welding cable, is mounted in an opening in a power supply chassis by means of front and rear bulkhead insulators that electrically isolate the receptacle from the chassis. However, sometimes water seeps between the front bulkhead insulator and the chassis. The water then seeps down between the front and rear bulkhead insulators. Additionally, a second potential water seepage path lies between the receptacle and the front bulkhead insulator. As water leaks in along either path, the water may provide a conductive path from the twist-lock receptacle, which is electrically hot, to the chassis, which should be grounded. Thus, either path for water leakage may provide an undesirable short circuit.
One prior art attempt to solve the problem of water leakage is to apply a room-temperature vulcanizing compound to seal the interstices that would otherwise provide a path for water leakage. Another solution, disclosed in U.S. Pat. No. 6,193,548, is to insert O-ring seals in the paths of water leakage surrounding the cable receptacle.
Yet another prior art solution is to attach a water-impermeable receptacle cover assembly to the chassis, which assembly comprises a lid coupled to an adapter or mounting ring by hinges that allow the lid to pivot between open and closed positions relative to the adapter. Alternatively, it is known to connect the lid to the adapter via a membrane or web of flexible material that forms a so-called xe2x80x9cliving hingexe2x80x9d. In either case, the receptacle, which projects through an aperture in the adapter or mounting ring, is enclosed by the water-impermeable receptacle cover when the lid is in the closed position. A gasket is provided between the chassis and the adapter to limit water leakage into the enclosure.
Some power supplies intended for outdoor usage have multiple receptacles of different sizes and shapes. It is known to provide a respective cover of different design for each style of receptacle. For example, a receptacle that has a rectangular socket end projecting through one opening in a housing or panel would be covered by a receptacle cover assembly in which the adapter has a matching rectangular aperture, while a receptacle that has a circular socket end projecting through another opening in the housing or panel would be covered by a different receptacle cover assembly in which the adapter has a matching circular aperture. Thus, the manufacture of such power supplies requires the manufacture and inventory of different styles of receptacle covers.
There is a need for a receptacle cover design that would reduce the cost of and simplify the process of manufacturing power supplies intended for use outdoors.
The invention is directed to a power supply interface comprising electrical receptacles and intended for use outdoors or some other environment in which the receptacles can be exposed to water. Universal receptacle covers are used to cover exposed socket ends of the receptacles that have different geometric configurations. The universal receptacle cover comprises an adapter having an aperture with a geometric configuration that allows socket ends of different geometric configurations to project through the aperture. This avoids the need for receptacle covers with different configurations to accommodate the different socket ends.
One aspect of the invention is a power supply interface comprising: a chassis having a first opening with a first geometric configuration and a second opening with a second geometric configuration different than the first geometric configuration; a first electrical receptacle mounted to the chassis and comprising a socket end that projects through the first opening and is designed to receive a plug of a first type; a second electrical receptacle mounted to the chassis and comprising a socket end that projects through the second opening and is designed to receive a plug of a second type different than the first type; a first receptacle cover comprising an adapter mounted to the chassis and a lid connected to the adapter by a living hinge, wherein the adapter comprises an aperture having a third geometric configuration different than the first and second geometric configurations, and the first receptacle cover covers the socket end of the first electrical receptacle when the lid of the first receptacle cover is coupled to the adapter of the first receptacle cover; and a second receptacle cover substantially identical in structure to the first receptacle cover, wherein the second receptacle cover covers the socket end of the second electrical receptacle when the lid of the second receptacle cover is coupled to the adapter of the second receptacle cover.
Another aspect of the invention is a power supply unit comprising: a generator capable of generating a first electrical power at a first output terminal and a second electrical power different than the first electrical power at a second output terminal; a chassis having a first opening with a first geometric configuration and a second opening with a second geometric configuration different than the first geometric configuration; a first electrical receptacle mounted to the chassis and electrically coupled to the first output terminal, the first electrical receptacle comprising a socket end that projects through the first opening and is designed to receive a plug of a first type; a second electrical receptacle mounted to the chassis and electrically coupled to the second output terminal, the second electrical receptacle comprising a socket end that projects through the second opening and is designed to receive a plug of a second type different than the first type; a first receptacle cover comprising an adapter mounted to the chassis and a lid connected to the adapter by a flexible web, wherein the adapter comprises an aperture having a third geometric configuration different than the first and second geometric configurations, and the first receptacle cover covers the socket end of the first electrical receptacle when the lid of the first receptacle cover is coupled to the adapter of the first receptacle cover; and a second receptacle cover substantially identical in structure to the first receptacle cover, wherein the second receptacle cover covers the socket end of the second electrical receptacle when the lid of the second receptacle cover is coupled to the adapter of the second receptacle cover.
A further aspect of the invention is a power supply interface comprising: a panel; a first electrical receptacle mounted to the panel and comprising a first socket end that has a first geometric configuration and is designed to receive a plug of a first type; a second electrical receptacle mounted to the panel and comprising a second socket end that has a second geometric configuration different than the first geometric configuration and is designed to receive a plug of a second type different than the first type; a first receptacle cover comprising an adapter mounted to the panel and a lid connected to the adapter by a flexible web, wherein the adapter comprises an aperture having a third geometric configuration different than the first and second geometric configurations, and the first receptacle cover covers the first socket end of the first electrical receptacle when the lid is coupled to the adapter; and a second receptacle cover substantially identical in structure to the first receptacle cover, wherein the second receptacle cover covers the second socket end of the second electrical receptacle when the lid of the second receptacle cover is coupled to the adapter of the second receptacle cover. In the foregoing arrangement, the first socket end of the first electrical receptacle projects through the aperture in the adapter of the first receptacle cover, while the second socket end of the second electrical receptacle projects through the aperture in the adapter of the second receptacle cover.
Yet another aspect of the invention is a method for waterproofing exposed first and second socket ends of first and second electrical receptacles mounted to a panel of a power supply unit, the first and second socket ends having different geometric configurations, respective major portions of the first and second electrical receptacles being disposed on one side of the panel, and the first and second socket ends projecting at least partly on the other side of the panel. The method comprises the following steps: molding first and second receptacle covers having substantially identical structure, each of the receptacle covers comprising an adapter with an aperture, a lid and a web connecting the lid to the adapter, the lid and the adapter forming a watertight seal when the lid is pressed onto the adapter, thereby closing the respective receptacle cover; and fastening the adapters of the first and second receptacle covers to the panel in respective positions such that the first receptacle cover in a closed state covers the first socket end as it projects through the aperture in the adapter of the first receptacle cover, while the second receptacle cover in a closed state covers the second socket end as it projects through the aperture in the adapter of the first receptacle cover.
Other aspects of the invention are disclosed and claimed below.